1. Field of the Invention
The present invention relates to an image processing apparatus that displays reduced images (hereinbelow, referred to as “thumbnail images”) representing each image when browsing images and that can display an index display, and a control method for the image processing apparatus.
2. Description of the Related Art
Image browsing apparatuses that display images formatted using JPEG (Joint Photographic Experts Group) and the like on personal computers and television devices and provide audio-visuals of an image to a user are becoming widespread. Such image processing apparatuses are called image viewers or image browsing devices. An image browsing device is generally provided with an index display function, displays a thumbnail image of each image arranged in plurality on one screen, and provides the user with an image selection interface. This index display function has the advantage that searching for a desired image is facilitated because a user can browse a plurality of images simultaneously and can actually confirm the image content.
In addition, in order to improve the search performance for a large number of images, technology has been proposed in which a user selects thumbnail images that are to be displayed on one screen by using, for example, the image capture times for each of the image, and the selected images are displayed as representative images (refer, for example, to Japanese Patent Laid-Open No. 2008-269490). In this technology, the images used in the index display are grouped by using the image capture time and the similarities between images (color, composition and the like), and a representative image for each group is displayed in an index display. Thereby, in the index display state, the number of operations the user must perform until the desired image is viewed can be reduced.
The index display function can search for a desired image while the user browses images, and on this point, it is superior to other image search functions. However, it is disadvantageous on the point that, in the case in which the desired image is arranged at a location distantly separated from the screen (index screen) in the current display, cost and labor (time, number of operations) are incurred in a search until a desired image is found. For example, in an image browsing apparatus having an index display function, assume a case in which twenty thumbnail images are displayed in one screen. In this image browsing apparatus, in the case in which 1000 images are browsed, 50 operations must be carried out even when a page skip function is used to move from the first to the last image. Note that a “page skip function” denotes a function that simultaneously updates all the images in one screen (20 images in the present example). In the technology that is disclosed in Japanese Laid Open Patent Application, Publication No. 2008-269490, the effect is obtained that the movement between a large number of images can be speeded up by displaying only representative images in the index display state. However, there is a problem in that the user cannot indicate an index for selecting the representative image that is displayed. Originally, there is a condition in which, in the case in which the user searches for images at a higher speed or the case in which the user wishes to search for images in more detail or the like, search conditions and the like that are appropriate for each situation cannot be provided.
It is an object of the present invention to provide an image processing apparatus that can efficiently carry out image search processing in an index display in a short time, and a control method for an image processing apparatus.